Borescope inspection method and device

Abstract

A method for borescope inspection of a component uses a stereo borescope for recording the component. The method includes: generating two stereoscopic partial images by means of the stereo borescope; calculating 3D triangulation data from the two stereoscopic partial images; registering the 3D triangulation data to a 3D CAD reference model of the component captured by the stereo borescope, while determining a projection point; projecting 2D image data determined from the two stereoscopic partial images onto the 3D CAD reference model from the determined projection point; and determining damage by image analysis of the projected 2D image data and by ascertaining deviations of the registered 3D triangulation data vis-à-vis the 3D CAD reference model.

The invention claimed is: 
     
       1. A method for borescope inspection of a component, wherein a stereo borescope is used for recording the component, the method comprising:
 generating two stereoscopic partial images by means of the stereo borescope; 
 calculating 3D triangulation data from the two stereoscopic partial images; 
 registering the 3D triangulation data to a 3D CAD reference model of the component captured by the stereo borescope, while determining a projection point; 
 projecting 2D image data determined from the two stereoscopic partial images onto the 3D CAD reference model from the determined projection point; and 
 determining damage by image analysis of the projected 2D image data and by ascertaining deviations of the registered 3D triangulation data vis-à-vis the 3D CAD reference model. 
 
     
     
       2. The method as claimed in  claim 1 , the method comprising:
 before calculating the 3D triangulation data, rectifying the two stereoscopic partial images on the basis of a predefined calibration. 
 
     
     
       3. The method as claimed in  claim 1 , the method comprising:
 adapting the 3D CAD reference model by the 3D triangulation data before the 2D image data are projected onto the 3D CAD reference model. 
 
     
     
       4. The method as claimed in  claim 1 ,
 wherein the 2D image data are generated by superimposing the stereoscopic partial images. 
 
     
     
       5. The method as claimed in  claim 1 ,
 wherein the projection point is determined beginning with a position of the stereo borescope that is determinable by a borescope guide device. 
 
     
     
       6. The method as claimed in  claim 1 ,
 the method comprising: 
 controlling a borescope guide device in such a way that all predefined regions of the component are captured sequentially by the stereo borescope, wherein the 3D triangulation data or the 2D image data generated in each case by way of the two stereoscopic partial images are combined with the aid of the 3D CAD reference model. 
 
     
     
       7. The method as claimed in  claim 1 ,
 wherein the component to be recorded is blades of a gas turbine, wherein a rotation angle position of the blades to be recorded are taken into account when registering the 3D triangulation data to the 3D CAD reference model. 
 
     
     
       8. The method as claimed in  claim 7 ,
 wherein the rotation angle position of the blades to be recorded is controlled in such a way that all blades of a turbine or compressor stage are captured. 
 
     
     
       9. A device for borescope inspection of a component, the device comprising:
 a stereo borescope; and 
 a computer connected to the stereo borescope and having access to a memory comprising a 3D CAD reference model, 
 wherein the device is configured to perform the method as claimed in  claim 1 . 
 
     
     
       10. The device as claimed in  claim 9 ,
 the device comprising a borescope guide device configured to guide the stereo borescope, the borescope guide device being connected to the computer unit, 
 wherein the device is configured such that:
 the projection point is determined beginning with a position of the stereo borescope that is determinable by a borescope guide device, or 
 the borescope guide device is controlled in such a way that all predefined regions of the component are captured sequentially by the stereo borescope, the 3D triangulation data or the 2D image data being generated in each case by way of the two stereoscopic partial images that are combined with the aid of the 3D CAD reference model. 
 
 
     
     
       11. The device as claimed in  claim 9 ,
 wherein 
 the device is configured to determine and to take account of a rotation angle position of blades of a gas turbine, as the component to be recorded, and 
 wherein the device is configured to either:
 take into account the rotation angle position when registering the 3D triangulation data to the 3D CAD reference model, or 
 control the rotation angle position of the blades to be recorded in such a way that all blades of a turbine or compressor stage are captured.